1. Field of the Invention
The present invention relates to a practice apparatus for a ball game, such as tennis and, more specifically, to a practice apparatus equipped with a main body which can control the range of the ball""s flight.
2. Description of the Prior Art
Because this kind of practice apparatus for ball games, such as tennis, is able to be used for exercise in a comparatively small space, it is convenient for a wide variety of players from beginners to experts. Practice apparatus with a wide variety of functions have been developed to simulate actual game conditions so that practice similar to an actual game condition can be experienced in order to improve one""s skill level. The present invention provides a practice apparatus that can achieve ball returns close to those which occur in actual play by selecting suitable elastic means for attaching to the ball without adopting conventional methods that depend only on the elasticity of rubber (U.S. Pat. Nos. 4,902,012, 5,098,094).
In the case of conventional techniques, in an effort to portray the flight condition of balls in actual play, the elastic means connected to the ball must have an excessive length and, consequently, a large distance is required from the column to the position of the hanging ball, resulting in an excessive height, and, thus, the entire apparatus becomes cumbersome, which is a distinct disadvantage.
In addition, because the ability to achieve a variety of returns depends on the fixed tilting angle provided at a rebounding board, there is no denying that returns are monotonous to a certain extent.
Another disadvantage in the conventional technique is that the length of elastic rope to which the ball is tethered becomes twisted because of the accumulation of ball rotations generated during lengthy practices. Due to this twist, the ball tethering length becomes excessively short or comes in contact with the rubber fixed to a frame at one point, creating the possibility of damage to the contact point.
Under these circumstances, it is the main object of the invention to provide a ball game practice apparatus which solves the problems of conventional techniques, and to reproduce the trajectory of a batted ball close to that of actual play without making the size of the apparatus unwieldy.
In addition, it is a further object of the invention to provide a ball game practice apparatus that can produce a variety of returned ball flights similar to those experienced in actual games.
It is a still further object of the invention to provide a ball game practice apparatus with an improved elastic means durability.
A ball game practice apparatus according to the invention comprises a ball, a practice apparatus main body from which the ball hangs and at the same time regulates the range of the flight of the ball, a frame mounted upon the practice apparatus main body that can hang the ball at a specific position via an elastic means, and a column for supporting this frame. The elastic means comprises a frame connection extending along the frame and further comprises a ball connection from which the ball hangs. The subject invention is characterized in that the frame connection of the elastic means mounted to the frame includes at least a pair of turned-back portions with a rotatable turn-back mechanism.
If the practice apparatus is configured in this way, when the elastic means extends as the ball is hit, the frame connection that is turned back from the turn-back portions has sufficient length and can eliminate resistance at the turn-back portion as much as possible, thereby allowing the elastic means to smoothly extend, recreating the trajectory of a ball when hit in actual game conditions. Even an exerciser who hits the ball hard and with great force may achieve satisfactory extension of the elastic means, and, thus, satisfactory height and distance of the ball. In addition, because the rebounding ball is returned with the elastic force of a sufficiently extended elastic means, it produces a natural effect.
It is preferable that the turn-back mechanism of the turn-back portion is isolated and turns back the frame connection in such a manner to avoid contact between passing portions of the frame connections.
In this way, it is possible to prevent generation of contact resistance caused by overlapping of frame connections, and the flight path of the ball can be more accurately simulated to actual game conditions. In addition, if the number of turn-back connections are increased to secure the extension rate of the frame connections, contact with the relevant elastic means that comprise these frame connections can be avoided. As a result, unnatural ball flight paths due to contact resistance between the elastic means does not occur, and it is possible for a person to more closely simulate actual play.
The frame may be configured to be rotatably pivoted to the column.
If the practice apparatus is configured in this way, hitting the ball hung on the frame rotates the frame around the axis of the column that supports the frame. It is therefore preferable that a wide range of trajectories for return balls like those in actual play can be obtained utilizing but without rearranging the rebounding board.
A rotation restrictor to limit the range of rotation of the frame that rotates around the column may be provided.
Because configuring in this way can restrict the range of motion of the frame on which the ball is hung, it is possible to carry out more controlled returns, and continuous rallies can be experienced, which are desirable in practice sessions.
In a preferred embodiment of the invention, the ball connection of the elastic means comprises a plurality of loops. Each of these loops is connected via a twist straightening mechanism. Furthermore, the contact position of the ball connection can be varied.
This configuration can eliminate detrimental effects caused by twisting of the elastic means arising from rotation of the elastic means even when the strongly hit ball is violently rotated. This configuration can improve the durability without generating damage to the elastic means, at the same time enabling the continuation of controlled ball hitting exercises. Even if the exercise is continued for a long time, it is possible to avoid contacting the ball in the same place by changing the contact position of the elastic means comprising the ball connection, effectively reducing wear and tear of the contact place, and remarkably improving the durability of the whole apparatus.
A rebounding board may be installed ahead of the flight path of the ball.
In the present invention, the rebounding board is not always required, but installing a rebounding board ahead of the flight path of the ball offers more variability in the trajectory of return balls, which is preferable.
When the ball rebounding board has a changeable surface angle, still more variability in the trajectory of return balls can be obtained, which is also preferable.
It is also possible to install a target equipped with a return prevention mechanism that captures the flown ball.
This configuration will assure that the ball hits the target even when it is difficult to verify at high speed.
A downward displacement restrictor for restricting the downward displacement of the frame connection of the elastic means may be installed to the frame of the invention.
Configuring in this way can restrict the downward displacement of the ball even when the ball is hit hard, and it is convenient that the return ball is easy to return to the original hung position.
The downward displacement restrictor installed near one end of the frame may comprise combinations of a plurality of annulus rings of varying sizes.
Configuring in this way can effectively reduce contact resistance between the elastic means and annular rings at individual annular rings because the ball load is distributed to a plurality of annular rings, and it is desirable that the flight of the ball upon being struck simulates an unrestricted, naturally struck ball.
It is preferable that at least one of the downward displacement restrictors is equipped with an isolating mechanism for reducing contact with the elastic means.
As the ball is hit, the elastic means connected to the ball is pulled with a strong force and comes in contact with the elastic means existing in parallel, but if the contact of these elastic means is excessive, resistance may be generated in movement of the elastic means or eventually damage to the elastic means may occur. As a result, the durability of the elastic means is detrimentally affected and at the same time, the flight path of the struck ball is restricted unnaturally, which is not desirable. Consequently, providing this kind of isolating mechanism not only increases the life of the elastic means but also permits the flight of the struck ball to simulate that of an actual struck ball.